Non-perturbative regime of QCD is dominated by the phenomena of quark confinement and spontaneous chiral symmetry breaking. Lattice simulations [1]}, [2]}, [3]}, [4]}, [5]}, [6]} and infrared models [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}, [14]}, [15]} have shown that center vortices [16]}, [17]}, [18]}, [19]}, [20]}, [21]}, quantized magnetic flux tubes in terms of the non-trivial center elements, cause the area law of the Wilson loop and therefore a linearly rising potential in the infrared regime. In addition, lattice simulations
have indicated that center vortices are also responsible for
the topological charge and spontaneous chiral symmetry breaking [22]}, [23]}, [24]}, [25]}, [26]}, [27]}, [28]}, [29]}, [30]}, [31]}. Neglecting dynamical quarks in the vacuum, there is two non-perturbative ranges of interquark distances with distinct behaviors. At intermediate distances, the string tension follows the Casimir scaling rule [32]}, [33]}, [34]} while the asymptotic string tension only depends on \(N\) -ality [35]}.
